Large scale manufacturing of target proteins using mammalian cells such as Chinese Hamster Ovary Cells (CHO) or other similar cells currently constitutes about three-fourth of all recombinant manufacturing methods used today. As more target proteins, particularly the monoclonal antibodies (MABs) come off patent, there is a rising unmet need for manufacturing systems that will be affordable, easily installed and operated with least burden of regulatory challenges. None of the currently used systems, regardless of their cost, offer these advantages. As an example, a mammalian cell manufacturing facility to provide at least 20% of the world market for a single MAB could cost over $100 Million for cGMP production. Needs for such large investment have kept many companies outside of this field of manufacturing resulting in monopolization and price controls for these products worldwide.
There is a large unmet need to develop methods for manufacturing of target protein at the lowest possible cost and these can be achieved by a novel combination of various concepts including:                a. Use of smaller bioreactors to create large batches by combining the output in compliance with CFR21 requirement of the definition of a cGMP batch, to reduce the cost of scaling up and validation, reduced cost of contamination failures and using smaller manufacturing facilities.        b. Eliminating the costly steps of cell separation, nutrient media volume reduction and lengthy chromatography column loading.        c. Allowing purification using either step or gradient elution.        d. Performing all of the above operations in a single container under fully automated conditions to allow for unattended operations.        
The instant invention provides a novel solution for cost-containment in target protein manufacturing by combining all of the above key elements in a novel system that can be used to manufacture mainly the type of target proteins which are secreted in the nutrient media, more particularly the large dose products like monoclonal antibodies with least capital cost requirement and with the lowest possible operating cost, and the shortest turn-around time for development and manufacturing of new products. More generally, the instant invention can be used to pool, harvest and purify any recombinant substance either as expressed or in any stage of purification. Representative examples will the pooling and concentration of target proteins target proteins at the stage of refolding of proteins.
The novel downstream processing system claimed is not an obvious outcome of the known art; several novel steps, hardware components and methods had to be created to make this system to function optimally.